#include <stdlib.h>
#include <strings.h>

#include "vars.h"
#include "pline.h"
#include "structs.h"

#include "util.h"

/*
 * None of these seem to me to call for remark beyond util.h's
 *  descriptions of their interface contracts.
 */

LOC *movecell(LOC *lc, int dx, int dy, int alwayswrap)
{
 int x;
 int y;
 LEVEL *lv;

 x = lc->x + dx;
 y = lc->y + dy;
 lv = lc->on;
 if ((x < 0) || (y < 0) || (x >= LEV_X) || (y >= LEV_Y))
  { if (alwayswrap || (lv->flags & LVF_WRAPAROUND))
     { if (x < 0) x += LEV_X; else if (x >= LEV_X) x -= LEV_X;
       if (y < 0) y += LEV_Y; else if (y >= LEV_Y) y -= LEV_Y;
     }
    else
     { panic("moving off edge in movecell");
     }
  }
 return(&lv->cells[x][y]);
}

int distance2(LOC *l1, LOC *l2)
{
 int dx;
 int dy;

 if (l1->on != l2->on)
  { panic("different levels to distance2");
  }
 dx = l1->x - l2->x;
 dy = l1->y - l2->y;
 if (l1->on->flags & LVF_WRAPAROUND)
  { if (dx < -LEV_X/2) dx += LEV_X; else if (dx > LEV_X/2) dx -= LEV_X;
    if (dy < -LEV_X/2) dy += LEV_Y; else if (dy > LEV_Y/2) dy -= LEV_Y;
  }
 return((dx*dx)+(dy*dy));
}

int distancei(LOC *l1, LOC *l2)
{
 int dx;
 int dy;

 if (l1->on != l2->on)
  { panic("different levels to distance2");
  }
 dx = l1->x - l2->x;
 dy = l1->y - l2->y;
 if (l1->on->flags & LVF_WRAPAROUND)
  { if (dx < -LEV_X/2) dx += LEV_X; else if (dx > LEV_X/2) dx -= LEV_X;
    if (dy < -LEV_X/2) dy += LEV_Y; else if (dy > LEV_Y/2) dy -= LEV_Y;
  }
 dx = abs(dx);
 dy = abs(dy);
 return((dx>dy)?dx:dy);
}

int vowel(char c)
{
 return(!!index("aeiouAEIOU",c));
}

int dirkey(int ch, int *xp, int *yp, XY *xyp, int *flagp, int flags)
{
 int x;
 int y;
 int f;

 switch (ch)
  { case 'h': x = -1; y =  0; f = 0; break;
    case 'j': x =  0; y =  1; f = 0; break;
    case 'k': x =  0; y = -1; f = 0; break;
    case 'l': x =  1; y =  0; f = 0; break;
    case 'y': x = -1; y = -1; f = 0; break;
    case 'u': x =  1; y = -1; f = 0; break;
    case 'b': x = -1; y =  1; f = 0; break;
    case 'n': x =  1; y =  1; f = 0; break;
    case 'H': x = -1; y =  0; f = DK_CAPS; break;
    case 'J': x =  0; y =  1; f = DK_CAPS; break;
    case 'K': x =  0; y = -1; f = DK_CAPS; break;
    case 'L': x =  1; y =  0; f = DK_CAPS; break;
    case 'Y': x = -1; y = -1; f = DK_CAPS; break;
    case 'U': x =  1; y = -1; f = DK_CAPS; break;
    case 'B': x = -1; y =  1; f = DK_CAPS; break;
    case 'N': x =  1; y =  1; f = DK_CAPS; break;
    case '\010'/*^H*/: x = -1; y =  0; f = DK_CTL; break;
    case '\012'/*^J*/: x =  0; y =  1; f = DK_CTL; break;
    case '\013'/*^K*/: x =  0; y = -1; f = DK_CTL; break;
    case '\014'/*^L*/: x =  1; y =  0; f = DK_CTL; break;
    case '\031'/*^Y*/: x = -1; y = -1; f = DK_CTL; break;
    case '\025'/*^U*/: x =  1; y = -1; f = DK_CTL; break;
    case '\002'/*^B*/: x = -1; y =  1; f = DK_CTL; break;
    case '\016'/*^N*/: x =  1; y =  1; f = DK_CTL; break;
    default: return(0); break;
  }
 if ((flags & DK_NOCTL) && (f & DK_CTL)) return(0);
 if ((flags & DK_NOCAPS) && (f & DK_CAPS)) return(0);
 if (xp) *xp = x;
 if (yp) *yp = y;
 if (xyp)
  { xyp->x = x;
    xyp->y = y;
  }
 if (flagp) *flagp = f;
 return(1);
}

int never_collapsible( OBJ *o1 __attribute__((__unused__)),
		       OBJ *o2 __attribute__((__unused__)) )
{
 return(0);
}

int never_identical( OBJ *o1 __attribute__((__unused__)),
		     OBJ *o2 __attribute__((__unused__)) )
{
 return(0);
}

/*
d    x  y   r rx ry   l lx ly   r45  x  y   l45  x  y

h   -1  0   k  0 -1   j  0  1    y  -1 -1    b  -1  1
k    0 -1   l  1  0   h -1  0    u   1 -1    y  -1 -1
l    1  0   j  0  1   k  0 -1    n   1  1    u   1 -1
j    0  1   h -1  0   l  1  0    b  -1  1    n   1  1

y   -1 -1   u  1 -1   b -1  1    k   0 -1    h  -1  0
u    1 -1   n  1  1   y -1 -1    l   1  0    k   0 -1
n    1  1   b -1  1   u  1 -1    j   0  1    l   1  0
b   -1  1   y -1 -1   n  1  1    h  -1  0    j   0  1
*/

XY turn_r(XY d)
{
 return((XY){ .x = -d.y, .y = d.x });
}

XY turn_l(XY d)
{
 return((XY){ .x = d.y, .y = -d.x });
}

XY turn_r45(XY d)
{
 if (d.x && d.y)
  { return((XY){ .x = (d.x-d.y)/2, .y = (d.y+d.x)/2 });
  }
 else
  { return((XY){ .x = d.x-d.y, .y = d.y+d.x });
  }
}

XY turn_l45(XY d)
{
 if (d.x && d.y)
  { return((XY){ .x = (d.x+d.y)/2, .y = (d.y-d.x)/2 });
  }
 else
  { return((XY){ .x = d.x+d.y, .y = d.y-d.x });
  }
}

const char *pickverb(MONST *m, const char *ifyou, const char *notyou)
{
 return((m==you)?ifyou:notyou);
}